What are the common symptoms of parasitic migration encephalitis?

Common symptoms include recurrent seizures, limb weakness, altered mental status, and loss of balance. If your pet becomes unconscious or has a prolonged seizure, seek emergency veterinary care immediately.

What tests will the vet run to find the cause?

The vet will typically perform a full neurological exam, blood tests, and urinalysis, and may recommend CT or MRI imaging where necessary, along with any additional tests based on the findings.

How should owners record symptoms before the vet visit?

Record when symptoms started and how they have progressed, note changes in appetite, water intake, and toileting, and film any seizures or gait abnormalities to show your vet.

Can parasitic migration to the brain be prevented?

Prevention includes routine deworming and reducing contact with intermediate hosts. Your vet can recommend the most suitable preventive regimen and frequency for your pet.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Parasitic Migration Encephalitis in Dogs & Cats: Seizures, Imaging & Treatment Guide [2025]

Parasitic migration encephalitis occurs when parasite larvae migrate into the brain, causing inflammation. Symptoms include seizures, paralysis, and altered consciousness. Treatment typically involves antiparasitic medication and steroids to control inflammation.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

PetHealthMap Editorial Team

Sources: WSAVA, AVMA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Generalized seizure lasting more than a few minutes
•Sudden loss of consciousness or prolonged coma
•Sudden hindlimb paralysis with inability to stand

Schedule a Clinic Visit Soon (within 24–72 hours)

•Intermittent seizures that are brief and self-resolving
•Markedly unsteady gait or head tilt
•Noticeably dull mentation or prolonged lethargy

01What symptoms indicate something is wrong?

When parasites migrate into the brain, dogs and cats commonly develop a range of central nervous system signs that may appear suddenly or progress gradually.

Recurrent or intermittent seizures, generalised convulsions
Weakness in one or more limbs, stumbling or dragging gait
Reduced alertness, lethargy, or confusion
Head tilt, poor balance, or a pronounced wobbly walk

Seek emergency care immediately if you notice the following symptoms:

⚠️ Sudden hind-limb collapse — unable to stand unassisted
⚠️ Continuous full-body seizure lasting more than a few minutes
⚠️ Loss of consciousness or prolonged unresponsive state

02How to assess your pet at home: key observations and when to go to emergency

Systematically recording your pet's condition at home before the visit helps the vet assess the situation quickly and decide which tests are needed.

Note the date and exact time symptoms first appeared
Write down changes in alertness, energy level, and behaviour
Record appetite, water intake, and toileting habits (frequency and consistency)
Film any seizures or abnormal walking on your phone and back up the footage

03How will the vet diagnose this? Common tests and examinations

The vet will use a neurological examination, laboratory tests, and imaging to assess whether the brain is affected.

Full neurological and physical exam to assess reflexes and function

Blood count and biochemistry panel to evaluate infection, inflammation, or organ status

Urinalysis to look for infection or parasite-related findings

CT or MRI scan when needed to identify brain lesions and extent of damage

04What treatment and care are needed? Medications, dietary adjustments, and home care

Treatment is tailored to the test results and generally includes addressing the underlying cause, supportive care, and regular follow-up.

The vet will devise a medication and supportive care plan based on test findings
Whether corticosteroids or other medications are needed will be determined by the vet
Severe cases may require hospitalisation with respiratory or cardiovascular support
Follow-up appointments to monitor neurological function and imaging changes

05What to prepare before the vet visit: key information to help the vet diagnose quickly

Write a timeline of when symptoms started and how they have changed

Bring a log of appetite, water intake, and toileting for the vet to review

Bring a list of all current and recent medications and supplements

Bring any recorded footage of seizures or abnormal gait and book an appointment promptly

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.